The present invention relates to fluid control valves, and more particularly to hydraulically controlled in-line valves.
Valves of the type referred to are usually mounted directly on the fluid line, however, with an interruption of the streamlined pipe configuration; a special fitting is installed for the purpose of mounting thereon the actuating device, be it a hydraulic or a solenoid operated control unit.
These non-streamlined mountable valves suffer an inherent disadvantage in that they cause turbulent, disturbed flow of fluid and entail the accumulation of dirt which, in the long run, affects the operation of the valve. Furthermore, because of their unbalanced construction, excessive wear and friction forces become present and cause unreliable operation.
It is therefore the major object of the invention to provide a fully balanced, streamlined in-line fluid flow control valve.
It is a further object of the invention that the valve according to the invention be provided with unidirectional self-closing means, converting same into a check valve in case of pressure breakdown at the upstream end of the line. It is a still further object of the invention that in such cases of pressure breakdown of the line and abrupt self-closing of the valve, the entailed "water hammer" effect should be reduced as far as possible.